U.S. patent application number 10/607698 was filed with the patent office on 2004-12-30 for patterned coating method.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to Free, M. Benton, Pekurovsky, Mikhail L..
Application Number | 20040265492 10/607698 |
Document ID | / |
Family ID | 33540349 |
Filed Date | 2004-12-30 |
United States Patent
Application |
20040265492 |
Kind Code |
A1 |
Free, M. Benton ; et
al. |
December 30, 2004 |
Patterned coating method
Abstract
Patterned articles can be prepared by applying a release polymer
to a substrate in a desired pattern, applying a substrate-adherent
polymer over the pattern and substrate, and mechanically removing
the substrate-adherent polymer from the pattern without requiring
solvent. Suitable mechanical removal methods include applying
adhesive tape to the substrate-adherent polymer and peeling the
tape and substrate-adherent polymer away from the pattern, and
abrading the substrate-adherent polymer from the pattern using
impact media.
Inventors: |
Free, M. Benton; (St. Paul,
MN) ; Pekurovsky, Mikhail L.; (Bloomington,
MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
33540349 |
Appl. No.: |
10/607698 |
Filed: |
June 27, 2003 |
Current U.S.
Class: |
427/256 ;
427/240; 427/420; 427/430.1 |
Current CPC
Class: |
B41M 5/0047 20130101;
H05K 3/0079 20130101; B41M 5/0064 20130101; B41M 1/12 20130101;
B41M 3/003 20130101; H05K 2203/0582 20130101; B41M 3/006 20130101;
H05K 2203/0264 20130101; B41M 1/34 20130101; H05K 2203/025
20130101; B41M 5/007 20130101; B41M 1/28 20130101; B41M 1/30
20130101; B41M 5/0058 20130101 |
Class at
Publication: |
427/256 ;
427/240; 427/420; 427/430.1 |
International
Class: |
B05D 003/12 |
Claims
We claim:
1. A method for preparing a patterned article comprising: a)
applying a release polymer to a portion of a substrate in a desired
pattern; b) applying a substrate-adherent polymer over the pattern
and over at least a portion of the substrate in a continuous layer
having a substantially constant height with respect to the
substrate; and c) mechanically removing the substrate-adherent
polymer from the pattern.
2. A method according to claim 1 wherein the release polymer has a
surface energy less than that of the substrate-adherent
polymer.
3. A method according to claim 1 wherein the release polymer
comprises a fluoropolymer.
4. A method according to claim 1 wherein the substrate-adherent
polymer comprises a polyimide.
5. A method according to claim 1 wherein the substantially constant
height is less than about 15 .mu.m.
6. A method according to claim 1 wherein the substantially constant
height is about 3 .mu.m to about 5 .mu.m.
7. A method according to claim 1 wherein the substantially constant
height is less than about 3 .mu.m.
8. A method according to claim 1 wherein the release polymer
pattern has a thickness and the substantially constant height is
about 2 to about 10 times the release polymer pattern
thickness.
9. A method according to claim 1 wherein the release polymer is
applied using inkjet coating, die coating or screen coating.
10. A method according to claim 1 wherein the substrate-adherent
polymer is applied using spin coating, dip coating, die coating or
curtain coating.
12. A method according to claim 1 wherein the substrate-adherent
polymer is removed from the pattern using impact media.
13. A method according to claim 1 wherein after the
substrate-adherent polymer is removed from the pattern the pattern
has at least one sidewall the major exposed portion of which is
substantially perpendicular to the substrate.
14. A method according to claim 1 wherein the patterned article
comprises a printed circuit board, electrical connector,
information display or electronic component.
15. A method for preparing a patterned article comprising: a)
applying a release polymer to a portion of a substrate in a desired
pattern; b) applying a continuous layer of a substrate-adherent
polymer over the pattern and over at least a portion of the
substrate; c) applying an adhesive tape to the substrate-adherent
polymer; and d) removing the adhesive tape and substrate-adherent
polymer adhered to the tape while leaving a portion of the
substrate-adherent polymer adhered to the substrate in a negative
of the pattern.
16. A method according to claim 15 wherein the release polymer has
a surface energy less than that of the substrate-adherent
polymer.
17. A method according to claim 15 wherein the release polymer
comprises a fluoropolymer.
18. A method according to claim 15 wherein the substrate-adherent
polymer comprises a polyimide.
19. A method according to claim 15 wherein the continuous layer has
a substantially constant height with respect to the substrate.
20. A method according to claim 19 wherein the substantially
constant height is less than about 15 .mu.m.
21. A method according to claim 19 wherein the substantially
constant height is about 3 .mu.m to about 5 .mu.m.
22. A method according to claim 19 wherein the substantially
constant height is less than about 3 .mu.m.
23. A method according to claim 19 wherein the release polymer
pattern has a thickness and the substantially constant height is
about 2 to about 10 times the release polymer pattern
thickness.
24. A method according to claim 19 wherein after removing the tape
the pattern has at least one sidewall the major exposed portion of
which is substantially perpendicular to the substrate.
25. A method according to claim 15 wherein the patterned article
comprises a printed circuit board, electrical connector,
information display or electronic component.
26. A method for preparing a patterned article comprising: a)
applying a submicron-thickness release polymer layer to a portion
of a substrate in a desired pattern; b) applying a continuous
submicron-thickness polyimide layer over the pattern and over at
least a portion of the substrate; and c) removing a portion of the
polyimide layer from the release polymer while leaving the
remainder of the polyimide layer adhered to the substrate in a
negative of the pattern.
27. A method according to claim 26 wherein the release polymer
comprises a fluoropolymer.
28. A method according to claim 26 wherein the thickness of the
polyimide layer is about 2 to about 10 times the release polymer
layer thickness.
29. A method according to claim 26 wherein after removing the
polyimide layer from the release polymer the pattern has at least
one sidewall the major exposed portion of which is substantially
perpendicular to the substrate.
Description
FIELD OF THE INVENTION
[0001] This invention relates to methods for forming patterned
coatings.
BACKGROUND
[0002] In many applications, especially those involving
electronics, patterned coatings must be formed in one or more
layers on a substrate. Available pattern formation methods include
masking the substrate with tape and photoimaging. In masking, a
tape is applied in a pattern over parts of the substrate. After
coating the substrate using any convenient method (e.g., spin
coating) and drying or curing the coating, the tape can be manually
removed, leaving the patterned coating. However, coating build-up
or edge distortion sometimes occurs near the pattern boundaries,
and applying and removing the tape can be tedious. In photoimaging,
a photocurable polymer is applied to the substrate, imaged in a
pattern (using, for example a partially transparent and partially
occluded mask and UV or shorter wavelength light), then removed
from the unimaged areas (in a step sometimes called "lift-off")
using a suitable solvent. The choice of suitable photoimaging
resins may be somewhat limited because many removal solvents may
adversely affect the photocured polymer coating. The removal
solvent may also pose environmental and other hazards.
[0003] References describing patterned coating or printed circuit
formation include U.S. Pat. Nos. 3,931,454, 5,121,134, 5,145,717
5,165,962, 5,658,469, 5,759,625, 6,300,042 B1, 6,329,227 B2,
6,498,114 B1 and 6,559,474 B1. U.S. Pat. No. 5,468,324 describes a
method for data recording duplication and microstructure
fabrication. U.S. Pat. No. 6,352,758 B1 describes a patterned
article. References involving masking include U.S. Pat. Nos.
5,104,711 and 5,165,962.
SUMMARY OF THE INVENTION
[0004] The present invention provides, in one aspect, a method for
preparing a patterned article comprising:
[0005] a) applying a release polymer to a portion of a substrate in
a desired pattern;
[0006] b) applying a substrate-adherent polymer over the pattern
and over at least a portion of the substrate in a continuous layer
having a substantially constant height with respect to the
substrate; and
[0007] c) mechanically removing the substrate-adherent polymer from
the pattern.
[0008] The invention provides, in another aspect, a method for
preparing a patterned article comprising:
[0009] a) applying a release polymer to a portion of a substrate in
a desired pattern;
[0010] b) applying a continuous layer of a substrate-adherent
polymer over the pattern and over at least a portion of the
substrate;
[0011] c) applying an adhesive tape to the substrate-adherent
polymer; and
[0012] d) removing the adhesive tape and substrate-adherent polymer
adhered to the tape while leaving a portion of the
substrate-adherent polymer adhered to the substrate in a negative
of the pattern.
[0013] The invention provides, in a further aspect, a method for
preparing a patterned article comprising:
[0014] a) applying a submicron-thickness release polymer layer to a
portion of a substrate in a desired pattern;
[0015] b) applying a continuous submicron-thickness polyimide layer
over the pattern and over at least a portion of the substrate;
and
[0016] c) removing a portion of the polyimide layer from the
release polymer while leaving the remainder of the polyimide layer
adhered to the substrate in a negative of the pattern.
BRIEF DESCRIPTION OF THE DRAWING
[0017] FIG. 1 is a cross-sectional view of a substrate partially
coated with a release polymer.
[0018] FIG. 2 is a cross-sectional view of the article of FIG. 1
overcoated with a substrate-adherent polymer.
[0019] FIG. 3 is a cross-sectional view of the article of FIG. 2
covered with an adhesive tape.
[0020] FIG. 4 is a cross-sectional view of the article of FIG. 3 as
the adhesive tape is being peeled away.
[0021] FIG. 5 is a cross-sectional view of the article of FIG. 3
after the adhesive tape has been peeled away.
[0022] FIG. 6 is a cross-sectional view of an impact media
technique for mechanically removing a portion of the
substrate-adherent polymer from the release polymer.
[0023] FIG. 7 through FIG. 11 are profilometer graphs.
DETAILED DESCRIPTION
[0024] By using the term "polymer" we refer to homopolymers and
copolymers, as well as to homopolymers or copolymers that may be
formed in a miscible blend, e.g., by coextrusion or by reaction,
including, e.g., transesterification. The term "copolymer" includes
both random and block copolymers.
[0025] By using the term "film former" we refer to a material that
can be coated in a thin film (e.g., of about 0.05 mm) on a suitable
substrate to form a substantially continuous coating.
[0026] By using words of orientation such as "atop", "on",
"uppermost" and the like for the location of various elements in an
article, we refer to the relative position of the element with
respect to a horizontal support or reference plane. We do not
intend that such elements or articles should have any particular
orientation in space during or after their manufacture.
[0027] By using the term "overcoated" to describe the position of a
layer with respect to a substrate or other element (e.g., an
underlying layer) in an article, we refer to the recited overcoated
layer as being atop the substrate or other element, but not
necessarily contiguous to the substrate or other element. By using
the term "separated by" to describe the position of a first element
with respect to two other elements, we refer to the first element
as being between the other elements but not necessarily contiguous
to either other element.
[0028] By using the term "surface energy" with respect to a
polymer, we refer to the measured surface energy of a thin film of
the polymer determined using a contact angle goniometer and two
test liquids as described in D. K. Owens and R. C. Wendt, J. Appl
Polym. Sci. 13, 1741 (1969).
[0029] By using the term "mechanically removing" with respect to a
polymer layer, we refer to removal methods that rely on adhesion
to, abrasion of or physical impact (including impact from a jet of
air, water or a solution containing water) upon the polymer layer
and that do not require (but can if desired be augmented by) the
application of an organic solvent to the polymer layer.
[0030] Referring to FIG. 1, patterned article 10 has glass
substrate 12 overcoated on a portion of its upper surface 13 with
release polymer 14. Release polymer 14 forms a pattern (not shown
in FIG. 1) on upper surface 13 representing, for example, circuit
traces, electrical connections, electrodes or the like. The upper
surface 15 of release polymer 14 preferably has a lower surface
energy than upper surface 13.
[0031] FIG. 2 illustrates an intermediate article 20 made by
applying substrate-adherent polymer 22 atop patterned article 10.
Substrate-adherent polymer 22 forms a continuous layer atop release
polymer 14 having a substantially constant height h with respect to
substrate 12. Release polymer 14 preferably has a sufficiently low
surface energy so that substrate-adherent polymer 22 forms at best
a weak bond to release polymer 14 that can readily be debonded
using mechanical measures described in more detail below.
Substrate-adherent polymer 22 has greater adhesion to substrate 12
than to release polymer 14.
[0032] FIG. 3 illustrates an intermediate article 30 made by
attaching adhesive tape 32 atop article 20. Adhesive tape 32 has
backing 34 and adhesive layer 36. Substrate-adherent polymer 22 has
greater adhesion to adhesive layer 36 than to release polymer 14,
but has lower adhesion to adhesive layer 36 than to substrate
12.
[0033] FIG. 4 illustrates one method for mechanically removing
substrate-adherent polymer 22 from the pattern atop substrate 12.
As shown by the arrow in FIG. 4, tape 32 can be peeled away from
substrate 12 to remove substrate-adherent polymer 42 adhered to
tape 32 while leaving substrate-adherent polymer 22 adhered to
substrate 12 in a negative of the pattern or "pattern negative".
This step provides patterned article 40 whose upper surface is
covered with a pattern formed by regions covered with release
polymer 14 and a pattern negative formed by regions covered with
substrate-adherent polymer 22.
[0034] FIG. 5 illustrates a patterned article 50 that can be made
by washing away release polymer 14 using a suitable solvent. This
washing step is optional and will not be needed or desired in all
applications. The upper surface of article 50 has a pattern formed
by exposed, uncovered regions (formerly covered by release polymer
14) and a pattern negative formed by regions covered with
substrate-adherent polymer 22.
[0035] FIG. 6 illustrates another method for mechanically removing
substrate-adherent polymer 22 from the pattern atop substrate 12.
This method can be carried out using article 20 shown in FIG. 2.
Impact media 62 propelled through orifice 64 in impact abrading
device 66 abrade away the portion of substrate-adherent polymer 22
atop release polymer 14. If desired, further application of impact
media 62 can be used to abrade away release polymer 14 as well.
[0036] A variety of substrates can be employed in the invention.
Suitable substrates include but are not limited to inorganic
substrates such as quartz, glass, silica and other oxides or
ceramics such as alumina, indium tin oxide, lithium tantalate
(LiTaO.sub.3), lithium niobate (LiNbO.sub.3), gallium arsenide
(GaAs), silicon carbide (SiC), langasite (LGS), zinc oxide (ZnO),
aluminum nitride (AIN), silicon (Si), silicon nitride
(Si.sub.3N.sub.4), and lead zirconium titanate ("PZT"); metals or
alloys such as aluminum, copper, gold, silver and steel;
thermoplastics such as polyesters (e.g., polyethylene terephthalate
or polyethylene naphthalates), polyacrylates (e.g., polymethyl
methacrylate or "PMMA"), poly(vinyl acetate) ("PVAC"),
poly(vinylbutyral) ("PVB)", poly(ethyl acrylate) ("PEA"),
poly(diphenoxyphosphazene) ("PDPP"), polycarbonate ("PC"),
polypropylene ("PP"), high density polyethylene ("HDPE"), low
density polyethylene ("LDPE"), polysulfone ("PS"), polyether
sulfone ("PES"), polyurethane ("PUR"), polyamide ("PA"), polyvinyl
chloride ("PVC"), polyvinylidene fluoride ("PVdF"), polystyrene and
polyethylene sulfide; and thermoset plastics such as cellulose
derivatives, polyimide, polyimide benzoxazole and polybenzoxazole.
Preferably care is taken when selecting the substrate so that there
will be an adequate degree of adhesion between the substrate and
the substrate-adherent polymer. If desired, the substrate can be
washed with a suitable solvent to enhance adhesion of the release
polymer or substrate-adherent polymer or both. The substrate can
instead or in addition to be pretreated to enhance such adhesion.
Preferred pretreatments include but are not limited to electrical
discharge in the presence of a suitable reactive or non-reactive
atmosphere (e.g., plasma, glow discharge, corona discharge,
dielectric barrier discharge or atmospheric pressure discharge);
chemical pretreatment (e.g., with a low solids solution of
polyvinylidene dichloride or with a solvent-borne mixture of a
polyester resin and an aziridine crosslinker); flame pretreatment;
ultraviolet light pretreatment with or without ozone pretreatment;
and incorporating functional polymers into the substrate when a
polymeric substrate is employed.
[0037] A variety of release polymers can be employed. Preferred
release polymers include but are not limited to silicone polymers,
fluorochemical polymers and polymers containing long alkyl side
chains. Suitable silicone polymers include silicone polyurethanes,
silicone polyureas, silicone polyurethane/ureas and silicone
acrylate grafted copolymers such as those described in U.S. Pat.
Nos. 4,728,571, 5,032,460, 5,202,190, 5,214,119, 5,290,615,
5,356,706 and 5,750,630. Suitable fluorochemical-containing
polymers include those described in U.S. Pat. No. 3,318,852.
Suitable polymers containing long alkyl side chains include
polyvinyl N-alkyl carbamates such as polyvinyl N-octadecyl
carbamates, and copolymers containing higher alkyl acrylates or
methacrylates such as octadecyl acrylate, stearyl methacrylate or
behenyl acrylate, e.g., those described in U.S. Pat. Nos.
2,532,011, 2,607,711, 3,502,497 and 4,241,198. In polymers
containing long alkyl side chains, the side chain preferably
includes from about 16 to 22 carbon atoms. The release polymer can
include additives such as fillers, pigments, wetting agents,
viscosity modifiers, stabilizers, anti-oxidants or cross-linking
agents. The release polymer can be formed in situ, or applied as a
preformed polymer carried in a suitable solvent. The release
polymer can be crosslinked if desired. As noted above, the release
polymer preferably has a sufficiently low surface energy so that
the substrate-adherent polymer forms at best a weak bond to the
release polymer. This does not require that the release polymer
have a lower surface energy than the substrate-adherent polymer. A
variety of factors other than surface energy may govern the degree
of adhesion between the release polymer and the substrate-adherent
polymer, including the respective chemical compositions of the
release polymer and substrate-adherent polymer and their respective
surface topologies. Preferably however the release polymer has a
surface energy less than that of the substrate-adherent polymer.
The release polymer preferably is a film former that can be applied
to form a coating that when dried or cured will have a thickness
below about 3 .mu.m, more preferably below about 2 .mu.m, and for
some applications a preferred submicron thickness. A variety of
coating techniques can be employed to apply the release polymer,
including swabbing, dip coating, roll coating, spin coating, spray
coating, die coating, ink jet coating, screen printing (e.g.,
rotary screen printing), gravure printing and flexographic
printing. If the release polymer is formed in situ, a variety of
techniques can be employed to form the release polymer including
exposure to heat, UV, electron beam or laser energy; two-part
chemical cure systems; one part chemical cure systems that are
prevented from premature cure by the use of a suitable blocking
agent or encapsulants; and other techniques that will be familiar
to those skilled in the art.
[0038] A variety of substrate-adherent polymers can be employed.
Preferred substrate-adherent polymers include but are not limited
to PMMA, PVAC, PVB, PEA, PDPP, fluoropolymers, epoxies,
polyhexamethyldisiloxane ("HMDSO"), polyimides and polystyrene. The
substrate-adherent polymer can include additives such as fillers,
pigments, wetting agents, viscosity modifiers, stabilizers,
anti-oxidants or cross-linking agents. The substrate-adherent
polymer can be formed in situ, or applied as a preformed polymer
carried in a suitable solvent. The substrate-adherent polymer can
be crosslinked if desired. Preferably the substrate-adherent
polymer has a surface energy greater than that of the release
polymer. As a general guide, the substrate-adherent polymer
preferably also has a surface energy greater than that of the
substrate. If desired, the substrate-adherent polymer can include
various adjuvants such as small particle fillers, surface active
agents, UV absorbers, photoinitiators, colorants and indicators.
The substrate-adherent polymer preferably is applied at a thickness
greater than that of the release polymer but not so great as to
make it difficult to remove the substrate-adherent polymer from the
pattern. As a general guide, the substrate-adherent polymer
thickness preferably is about 2 to about 10 times the release
polymer thickness, and more preferably about 3 to about 7 times the
release polymer thickness. As a further general guide, the
substrate-adherent polymer preferably is a film former that can be
applied to form a coating that when dried or cured will have a
thickness with respect to the substrate of about 3 .mu.m to about
15 .mu.m, more preferably about 3 to about 10 .mu.m, and most
preferably about 3 to about 5 .mu.m.
[0039] The substrate-adherent polymer is applied in a continuous
layer over the pattern. This preferably provides a smooth,
continuous substrate-adherent polymer coating having a
substantially constant height with respect to the substrate. If the
substrate-adherent polymer coating is not sufficiently thick to
cover the release polymer pattern then it will not provide a
continuous layer over the release polymer pattern having a
substantially constant height with respect to the substrate and the
eventual edges or margins of the pattern negative may be uneven or
otherwise inadequately defined, or the pattern may exhibit edge
artifacts.
[0040] A variety of coating techniques can be employed to apply the
substrate-adherent polymer including those mentioned above with
respect to the release polymer. If the substrate-adherent polymer
is formed in situ, a variety of polymerization techniques can be
employed including those mentioned above with respect to the
release polymer.
[0041] The substrate-adherent polymer can be removed from the
pattern using a variety of mechanical methods. Suitable mechanical
removal methods include but are not limited to the use of adhesive
tape or impact media as described above, as well as the use of low
impact or high impact coating dislodgment aids such as sandpaper,
buffing pads, pressurized air and ultrasonic horns. Mechanical
removal may facilitate the formation of a pattern having sharply
defined edges. Following removal of the substrate-adherent polymer,
the release polymer can be left atop the substrate or if desired
can also be removed, thereby exposing a portion of the substrate. A
variety of removal techniques can be employed, including but not
limited to the use of solvents or impact media as described above,
as well as the use of other coating dislodgement aids such as those
just described for removal of the substrate-adherent polymer. When
a solvent is employed, the solvent selection will depend in part
upon the chosen release polymer. For fluoropolymers,
hydrofluoroethers are particularly preferred removal solvents.
[0042] The invention can be used to make a variety of patterned
articles including printed circuit boards, electrical connectors,
information displays, electronic components, passivation layers and
dielectric layers.
[0043] The invention is further illustrated in the following
illustrative examples, in which all parts and percentages are by
weight unless otherwise indicated.
EXAMPLE 1
[0044] Using a hand-held cotton swab, generally C-shaped and
generally straight streaks of FLUORAD.TM. FC-722 fluoroaliphatic
copolymer coating (formerly commercially available from Dyneon LLC
Oakdale, Minn.) were formed on the surface of a 50 mm.times.75
glass slide. A rapid application rate was employed in order to
obtain a release polymer coating thickness of about 0.1 .mu.m as
measured using a TENCOR.TM. profilometer (commercially available
from KLA-Tencor Corporation, San Jose, Calif.). FIG. 7 shows the
profilometer scan. In cross-section the release polymer coating
looked like coating 14 in FIG. 1.
[0045] Using a spin-coating apparatus operated at 6000 rpm, No. PI
2579B polyimide (commercially available from HD Microsystems LLC,
Parlin, N.J.) was coated over the pattern and over the remainder of
the substrate to form a substrate-adherent polymer coating having a
substantially constant height of about 0.3 .mu.m with respect to
the substrate. In cross-section the resulting article looked like
article 20 in FIG. 2. A piece of Scotch Transparent Tape 600
(commercially available from 3M Company, St. Paul, Minn.) was
placed atop the polyimide coating over the pattern and pressed into
place to form an article which in cross-section looked like article
30 in FIG. 3. The tape was peeled away from the substrate as shown
in FIG. 4, thereby removing the substrate-adherent polymer from
atop the release polymer pattern and forming a patterned article
which in cross-section looked like article 40 in FIG. 4. FIG. 8
shows a profilometer scan of the patterned article. As shown in
FIG. 8, the edges of the pattern negative were sharply defined with
the major exposed portion of each sidewall being generally
perpendicular to the substrate, and both the release polymer
nominal coating thickness and the substrate-adherent polymer
nominal coating thickness were generally unchanged near the
boundary between the release polymer and substrate-adherent
polymer.
[0046] The fluoropolymer layer was removed from the patterned
article by rinsing with NOVEC.TM. Engineered Fluid HFE-7200
hydrofluoroether (commercially available from 3M Company, St. Paul,
Minn.) to form a patterned article which in cross-section looked
like article 50 in FIG. 5. FIG. 9 shows a profilometer scan of the
patterned article. The edges of the pattern negative remained
sharply defined with the major exposed portion of each sidewall
remaining generally perpendicular to the substrate.
EXAMPLE 2
[0047] Using the general method of Example 1, a fluoropolymer
release polymer pattern was formed on a glass slide. The release
polymer was overcoated with a solvent-based ink applied by dip
coating to form a 0.5 .mu.m thick substrate-adherent polymer
coating. A portion of the substrate-adherent polymer was removed
using tape, and the underlying release polymer was removed using
HFE-7200 hydrofluoroether. FIG. 10 and FIG. 11 show profilometer
scans of the patterned article before and after removal of the
release polymer. As shown in FIG. 10 and FIG. 11, the
substrate-adherent polymer edges were sharply defined with the
major exposed portion of each sidewall being generally
perpendicular to the substrate.
[0048] Various modifications and alterations of this invention will
be apparent to those skilled in the art without departing from the
scope and spirit of this invention. This invention should not be
restricted to that which has been set forth herein only for
illustrative purposes.
* * * * *